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Direct liquid fuel cells represent one of the most rapidly emerging energy conversion devices. The main challenge in developing fuel cell devices is finding low-cost and highly active catalysts. In this work, PET bottle waste was transformed into nitrogen-doped graphene (NG) as valuable catalyst support. NG was prepared by a one-pot thermal decomposition process of mineral water waste bottles with urea at 800 °C. Then, NG/Pt electrocatalysts with Pt loadings as low as 0.9 wt.% and 1.8 wt.% were prepared via a simple reduction method in aqueous solution at room temperature. The physical and electrochemical properties of the NG/Pt electrocatalysts are characterized and evaluated for application in direct borohydride peroxide fuel cells (DBPFCs). The results show that NG/Pt catalysts display catalytic activity for borohydride oxidation reaction, particularly the NG/Pt_1, with a number of exchanged electrons of 2.7. Using NG/Pt composite in fuel cells is anticipated to lower prices and boost the usage of electrochemical energy devices. A DBPFC fuel cell using NG/Pt_1 catalyst (1.8 wt.% Pt) in the anode achieved a power density of 75 mW cm−2 at 45 °C. The exceptional performance and economic viability become even more evident when expressed as mass-specific power density, reaching a value as high as 15.8 W mgPt−1.

A direct borohydride fuel cell (DBFC) is a type of low temperature fuel cell, and to commercialize this type of fuel cell, it requires efficient and inexpensive proton exchange membranes. In this study, a binary polymer blend is formulated from inexpensive and ecofriendly polymers such as iota carrageenan (IC) and polyvinyl alcohol (PVA). Zirconiam phosphate (ZrPO4) was synthesized from a simple impregnation — calcination method and later embedded as a doping agent into the polymeric matrix with percentage (1–7.5) wt.%. The novel nanocomposite membranes were evaluated by TGA, DSC, FTIR, XRD and SEM. The oxidative stability and tensile strength of the obtained membranes were enhanced and achieved results better than those of Nafion117 due to an increase in the number of hydrogen bonds formed between the polymer functional groups and oxygen functional groups of ZrPO4with increasing doping concentration. In addition, the borohydride permeability of the membranes decreased with increasing ZrPO4weight percentage, while the ionic conductivity and power density increased to 25.5 mS cm−1 and 66 mW cm−2, respectively, for membrane with 5 wt.% of ZrPO4. The fabricated membrane with the optimum properties (PVA/IC/ZrPO4− 5) can be efficient as a proton exchange membrane towards the development of green and low cost DBFCs.

Nanocomposite membranes for low-temperature fuel cells, specifically, direct borohydride fuel cells (DBFCs), are formulated from a ternary polymer blend of poly (vinyl alcohol), poly (vinyl pyrrolidone), and poly (ethylene oxide) with the incorporation of (SO4–TiO2) nanotubes and (PO4–TiO2) as doping agents. The functionalisation of TiO2 is carried out by impregnation-calcination method. Structural and morphological characterisation by FTIR, TEM, SEM, EDX, ICP, and XRD confirmed the successful preparation of the doping materials and their incorporation into the polymer blend. The influence of SO4–TiO2 and PO4–TiO2 doping and their content on the physicochemical properties of the composite membranes is assessed. Water uptake and swelling degree gradually reduced to below 20% with increasing the concentration of TiO2-based doping agent, while the ion exchange capacity raised 3.5 times compared to that of the undoped membrane. The increase of the doping agent content also increased the ionic conductivity, tensile strength and thermal stability of the membrane. DBFC using the composite membrane produced a maximum power density of 75 mW cm−2, close to that using Nafion®117 membrane (81 mW cm−2) but at a significantly lower cost. The promising results obtained in this study pave the way for a simple, green and economic approach for the development of composite membranes for application in DBFCs.

In our daily lives and product manufacturing, metal corrosion causes significant economic losses. Numerous polymeric composite coatings have been shown to be resistant to harsh environments, such as those found in marine environments. In this study, a composite of polyvinyl alcohol/polyaniline blend loaded with carboxylated graphene was explored in the search for long-lasting coatings to resist electrochemical deterioration of cast iron in desalination systems of saltwater. Polyvinyl alcohol/polyaniline/carboxylated graphene oxide nanocomposite was spin-coated onto cast iron samples. Electrochemical impedance spectroscopy (EIS) and electrochemical DC corrosion testing with a three-electrode system were used to study corrosion resistance in uncoated and coated cast iron samples. The results exhibit effective corrosion protection properties. The EIS data indicated better capacitance and higher impedance values for coated samples than bare metal, depicting enhanced corrosion resistance against the saline environment. Tafel analysis confirmed a significant decrease in the corrosion rate of the PVA/PANI/GO-COOH coated sample.

Effective and efficient removal of both heavy metal pollutants and bacterial contamination from fresh water is an open issue, especially in developing countries. In this work, a novel eco-friendly functional composite for water treatment application was investigated. The composite consisted of electrospun nanofiber membrane from blended polyvinyl alcohol (PVA)/iota carrageenan (IC) polymers doped with equal concentrations of graphene oxide (GO) nanoparticles and polyaniline (PANI). The effectiveness of this composite as a water purification fixed-bed filter was optimized in a batch system for the removal of cadmium (Cd+2) and lead (Pb+2) ions, and additionally characterized for its antimicrobial and antifungal properties and cytotoxicity effect. The fiber nanocomposite exhibited efficient antibacterial activity, with maximum adsorption capacity of about 459 mg g−1 after 120 min for Cd+2 and of about 486 mg g−1 after 90 min for Pb+2. The optimized conditions for removal of both metals were assessed by using a response surface methodology model. The resulting scores at 25 °C were 91.4% (Cd+2) removal at 117 min contact time for 89.5 mg L−1 of initial concentration and 29.6 cm2 membrane area, and 97.19% (Pb+2) removal at contact time 105 min for 83.2 mg L−1 of initial concentration and 30.9 cm2 nanofiber composite membrane. Adsorption kinetics and isotherm followed a pseudo-second-order model and Langmuir and Freundlich isotherm model, respectively. The prepared membrane appears to be promising for possible use in domestic water purification systems.

The direct borohydride fuel cell (DBFC) is a low-temperature fuel cell that requires the development of affordable price and efficient proton exchange membranes for commercial purposes. In this context, super-acidic sulfated zirconia (SO4ZrO2) was embedded into a cheap and environmentally friendly binary polymer blend, developed from poly(vinyl alcohol) (PVA) and iota carrageenan (IC). The percentage of SO4ZrO2 ranged between 1 and 7.5 wt.% in the polymeric matrix. The study findings revealed that the composite membranes’ physicochemical features improved by adding increasing amounts of SO4ZrO2. In addition, there was a decrease in the permeability and swelling ratio of the borohydride membranes as the SO4ZrO2 weight% increased. Interestingly, the power density increased to 76 mW cm−2 at 150 mA cm−2, with 7.5 wt.% SO4ZrO2, which is very close to that of Nafion117 (91 mW cm−2). This apparent selectivity, combined with the low cost of the eco-friendly fabricated membranes, points out that DBFC has promising future applications.

Polyaniline (PANI) in the nano form was prepared by a simple sol–gel method. The prepared PANI was carbonized under a direct nitrogen gas carbonization method to produce carbonized polyaniline (C-PANI). The difference in morphology and structure of the two prepared materials were studied and characterized for structure and morphological analysis by FT-IR spectrometry, X-ray diffractometry, scanning, and transmission electron microscopy. The Nano-PANI and C-PANI had a pore diameter of 84.96 and 90.86 nm which surface areas of 18.8 and 14.42 m2/g respectively. The prepared Nano-PANI was in emeraldine salt state; C-PANI was completely carbonized. The prepared materials were applied as electrode coating materials on the copper sheet which acted as a substrate and it produced a uniform smooth coating. This is promising and can further be studied for electrochemical applications. Further work is ongoing to ascertain its’ electrochemical capacitance properties. The method of preparation of the Nano-PANI and Nano C-PANI is eco-friendly and simple for the production of mass material for industrial purposes.

The development of bi-functional, non-precious and highly active catalyst has been a key challenge for the commercial application of alkaline fuel cells. In this work, fullerene iron oxide composite, derived from mineral water waste bottles, was used as a catalyst for electrodes in an alkaline fuel cell instead of platinum. The results demonstrate that an oxygen reduction reaction (ORR) was established to proceed through the efficacious four-electron reduction path, and all the reaction steps were found to be spontaneous. Interestingly, fullerene iron oxide composite is a promising electrocatalyst with bi-functional activity for ORR and oxygen evolution reaction in addition to achieving good cycling stability compared to platinum in the alkaline electrolyte.

The proton exchange membrane is the main component of direct methanol fuel cells (DMFCs). It has binary function of separating oxidant and fuels, besides transporting protons. In this study, a binary polymer blend is formulated from inexpensive and ecofriendly polymers, such as iota carrageenan (IC) and poly vinyl alcohol (PVA). Super acidic sulfated zirconia (SO4ZrO2) was synthesized from an one pot, solvent free and simple calcination method and later embedded as a doping agent into the polymeric matrix with a percentage of 1–7.5 wt. %. The membranes formed were characterized by FTIR, TGA, DSC and XRD. The results revealed that, the oxidative stability and mechanical properties were enhanced with increasing doping addition due to an increase in numbers of hydrogen bonds formed between the polymers functional groups and oxygen functional groups of SO4 ZrO2. In addition to, the membrane with doping ratio of 7.5 wt. % of SO4 ZrO2 achieved methanol permeability of 1.95 × 10–7 cm2 s−1 which much less than Nafion 117 ( 14.1 × 10–7 cm2 s−1) and ionic conductivity of 22.3 mS cm−1 which is close to Nafion 117 (34 mS cm−1).

Several reinforcement materials are incorporated into a polymeric matrix to improve the mechanical properties and reduce the cost of the obtained composites. In this work, recycled high-density polyethylene/waste glass powder composites, compatibilized with maleic anhydride-grafted polyethylene, were prepared using a two-roll mill and compression molding techniques. Four levels of waste glass powder, 2, 10, 20 and 30% by weight, and five levels of the compatibilizer, polyethylene grafted with maleic anhydride (0.5, 1.5, 2.5, 5 and 7.5%by weight), were used. The effect of adding waste glass powder and compatibilizer concentration on the composite's mechanical properties, such as tensile strength, tensile strain, tensile modulus and thermal properties was studied. The results showed that superior mechanical properties were obtained and that the tensile strength and modulus increased with increasing waste glass powder content and compatibilizer concentration by 20 and 1.5 wt%, respectively. However, the elongation at the break decreased with the increase in both factors. The composite, which was prepared under ideal conditions, has high thermal stability and can be easily recycled and reprocessed for five cycles with high mechanical properties. This study recommends that the prepared composite, under optimum conditions, can be used as a cost-effective automobile dashboard material., High density polyethylene; maleic anhydride compatibilizer; glass powder; thermoplastic composite; mechanical modulus.

The present research focuses on providing a novel facile, cost-effective and eco-friendly method for the mass production of N-doped graphene-like nanosheets (NGLs), in order to industrially benefit the exploitation of N-doped graphene in electronics, which will lead to the remarkable prosperity of graphene-based nanoelectronics. NGLs have been synthesized through a one-pot single-step process involving hydrolysis/hydrothermal treatment of glucose under mild conditions, using cetyltrimethylammonium bromide (CTAB) and ammonia solution (NH4OH) as the structure-directing agents. NGLs of high yield (65 wt%) and fascinating structural features, including low oxidation level, good crystalline structural order, and large laterally sized and well-exfoliated nanosheets, have been produced. The growth mechanism has been deeply investigated. The impressive chemical nature of CTAB has a synergistic effect in controlling the NGL structure. The cationic head of CTAB and anionic OH- ions resulting from NH4OH ionization have formed a passivating layer that played a profound role in hindering the NGL agglomeration and allowing the NGLs to grow into large lateral dimensions. Meanwhile, the polar (mainly H-bonding) and apolar (hydrophobic) interfacial interactions between the passivating layer and the graphitic network can be mainly considered responsible for the mild disturbed structural order inside the sp2 crystals. On the other hand, the excessive decomposition of CTAB that is also accompanied by fair ammonia decomposition during the hydrothermal treatment resulted in plenty of hydrogen and nitrogen gases in the atmosphere. The nitrogen gas N-doped the graphitic structure and the hydrogen gas effectively deoxygenated it. Furthermore, the high evolution rate of gases throughout the synthesis system contributed to the obstruction of NGL agglomeration. These results emphasize the high yield and good quality of the synthesized NGLs, which makes such a strategy promising in trust acquisition for investors in industrial production of N-doped graphene.

Tungsten oxide nanostructures were modified by oxygen vacancies through hydrothermal treatment. Both the crystalline structure and morphological appearance were completely changed. Spherical WO3&middot, H2O was prepared from tungstic acid solution by aging at room temperature, while rod-like WO3&middot, 0.33H2O was prepared by hydrothermal treatment of tungstic acid solution at 120 &deg, C. These structures embedded in sodium alginate (SA)/polyvinylpyrrolidone (PVP) were synthesized as novel porous beads by gelation method into calcium chloride solution. The performance of the prepared materials as photocatalysts is examined for methylene blue (MB) degradation in aqueous solutions. Different operation parameters affecting the dye degradation process, such as light intensity, illumination time, and photocatalyst dosage are investigated. Results revealed that the photocatalytic activity of novel nanocomposite changed with the change in WO3 morphology. Namely, the beads with rod nanostructure of WO3 have shown better effectiveness in MB removal than the beads containing WO3 in spherical form. The maximum degradation efficiency was found to be 98% for WO3 nanorods structure embedded beads, while the maximum removal of WO3 nanospheres structure embedded beads was 91%. The cycling-ability and reuse results recommend both prepared structures to be used as effective tools for treating MB dye-contaminated wastewaters. The results show that the novel SA/PVP/WO3 nanocomposite beads are eco-friendly nanocomposite materials that can be applied as photocatalysts for the degradation of cationic dyes in contaminated water.

The presence of pharmaceutical residues in aquatic environments represents a risk for the equilibrium of the ecosystem and may seriously affect human safety itself in the long term. To address this issue, we have synthesized functional materials based on highly-reduced graphene oxide (HRGO), sulfonated graphene (SG), and magnetic sulfonated graphene (MSG). The method of synthesis adopted is simple and inexpensive and makes use of plastic bottle waste as the raw material. We have tested the fabricated materials for their adsorption efficiency against two model antibiotics in aqueous solutions, namely Garamycin and Ampicillin. Our tests involved the optimization of different experimental parameters of the adsorption process, such as starting antibiotic concentration, amount of adsorbent, and time. Finally, we characterized the effect of the antibiotic adsorption process on common living organisms, namely Escherichia coli DH5&alpha, (E.coli DH5&alpha, ) bacteria. The results obtained demonstrate the efficiency of the method in addressing the issue of the emergence of antibiotic-resistant bacteria, which will help in preventing changes in the ecosystem.

A direct borohydride fuel cell (DBFC) is a type of low temperature fuel cell which requires efficient and low cost proton exchange membranes in order to commercialize it. Herein, a binary polymer blend was formulated from inexpensive and ecofriendly polymers, namely polyethylene oxide (PEO) and poly vinyl alcohol (PVA). Phosphated titanium oxide nanotube (PO4TiO2) was synthesized from a simple impregnation–calcination method and later embedded for the first time as a doping agent into this polymeric matrix with a percentage of 1–3 wt%. The membranes’ physicochemical properties such as oxidative stability and tensile strength were enhanced with increasing doping addition, while the borohydride permeability, water uptake, and swelling ratio of the membranes decreased with increasing PO4TiO2 weight percentage. However, the ionic conductivity and power density increased to 28 mS cm−1 and 72 mWcm−2 respectively for the membrane with 3 wt% of PO4TiO2 which achieved approximately 99% oxidative stability and 40.3 MPa tensile strength, better than Nafion117 (92% RW and 25 MPa). The fabricated membrane with the optimum properties (PVA/PEO/PO4TiO2-3) achieved higher selectivity than Nafion117 and could be efficient as a proton exchange membrane in the development of green and low cost DBFCs.

Herein, a facile and economic method was demonstrated for the synthesis of a novel mixed metal oxides, Cs doped ZrV2O7 in form of nanorods, with a cubic structure by precipitation-hydrothermal assisted microwave processes. Doping monovalent cations such as Cs ions played a crucial role in tuning the particles into rods and decreasing the optical bandgap that improves the photocatalytic activity. On the other hand, microwave treatment increased the bandgap and grain size of samples. The enhanced photocatalytic activity of the ZrV2O7 nanorods also offers the potential applications in ion exchangers and sensors.

Plastic wastes and industrial effluents cause a huge potential risk on the environment and insequencly affect on the human health. Accordingly, this research proposed an innovative facile, green, one-step and solvent-free strategy to a large-scale synthesis of functionalized magnetic fullerene nanocomposite (FMFNc) via catalytic thermal decomposition of sustainable poly(ethylene terephthalate) (PET) bottle wastes as a feedstock and ferrocene as a catalyst and precursor of magnetite nanoparticles. The growth mechanism of FMFNc was discussed and supported by extensive characterization in addition to the adsorption reactivity toward cationic, Methylene Blue dye (MB), and anionic dyes, Acid Blue 25 dye (AB25), was tested. Furthermore, the Response Surface Methodology model (RSM) was used to develop an approach for the evaluation of dye adsorption process via investigation of the effect of three variables as dye concentration, time and temperature. Moreover, ten cyclic adsorption-desorption processes were conducted to study the regenerability and reuse of the prepared FMFNc. The adsorption mechanism was confirmed by the study of surface chemistry before and after adsorption and was attained mainly via electrostatic interaction, π-π stacking interaction and hydrogen bonding. The “wastes-treat-wastes” idea was used to purify dye-contaminated wastewater and it was found that, the obtained FMFNc can be used as a promising alternative prospect of cheap adsorbent materials.

Numerous of pollutants threaten our planet, for instance plastic wastes causes a huge potential risk on the environment in addition to many of emergened pollutants as pharmaceutical residue in aquatic environments which affecting ecological balance and in-turn affecting human health. Accordingly, this research proposed an innovative facile, one-step synthesis of functionalized magnetic fullerene nanocomposite (FMFN) via catalytic thermal decomposition of sustainable poly (ethylene terephthalate) bottle wastes as feedstock and ferrocene as a catalyst and precursor of magnetite. Growth mechanism of FMFN was discussed and batch experiments were achieved to examine its adsorption efficiency in relation to Ciprofloxacin antibiotic. Different adsorption parameters including time, initial Ciprofloxacin concentration, and solution temperature were investigated and optimized using Response Surface Methodology (RSM) model. In addition, a study on the antibiotic adsorption process impact on the organisms of an ecosystem was conducted using E. coli DH5α, and results validated method's efficiency in overcoming problem of appearance of antibiotic-resistant microbes.

Developing low cost and highly active fuel cell is one of the high-priority research directions for fuel cell commercialization, whereas durable electrodes and electrolyte membranes are keys for its optimization. Herein, a novel nanocomposite electrolyte membranes for direct methanol fuel cell were prepared from eco-friendly polymer blend composed of poly(vinyl alcohol) (PVA) and iota carrageenan (IC). Sulfated titania (SO4TiO2) nanotubes are synthesized by impregnation–calcination method and incorporated as doping agents into the polymer matrix with different percentage ranged between 1 wt% and .5 wt%. The PVA/IC/SO4TiO2 nanocomposite membranes exhibited reduction in water and methanol uptake compared to that of undoped membrane, while the thermal properties and oxidative stability increased as the doping agent content increased. Methanol permeability of PVA/IC/[Formula: see text]-TiO2-7.5 membrane was 0.62 × 10−7 cm2 s−1, which is 43 times lower than Nafion 117 (26.9 × 10−7 cm2 s−1). Furthermore, it was noticed that the ion exchange capacity and mechanical properties of the nanocomposite membranes are higher than that of Nafion 117.